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Number Systems

Binary​

  • 45 in Decimal: 4 * 10^1 + 5 * 10^0
  • 45 in Binary: 101101 = 1*2^5 + 1*2^3 + 1*2^2 + 1*2^0 = 32 + 8 + 4 + 1 = 45
  • 45 in Hex: 2D = 2*16^1 + D*16^0 = 32 + 13 = 45

Prefixes/suffixes​

  • 0x means hex
  • b or B is binary
  • Many others depending on use-case

Common Data Types:​

Boolean: true/false​

  • Binary numbers w/ all 0 are false
  • Anything else is true
  • AND: true && true = true, false && true = false
  • OR: true && true = true, false && true = true, false && false = false
  • XOR: true && true = false, false && true = true, true && false = true, false && false = false

Numbers:​

  • Integers: {-inf..inf} only whole numbers (can be negative or positive unless unsigned)
    • Signed numbers use the first bit for the sign, where 1 is negative, and 0 is positive.
    • Unsigned numbers have no sign bit, so they are always positive
  • Float: {-inf..inf} with all decimals in between. Stored like: .5 -> 1 * 2^(-1)

Characters:​

  • ASCII: 7 bits, letters, digits, punctuation and some control characters
  • Unicode: 32 bits, aims to represent every written language, 100k+ characters